A process is known, in which poorly coking coal and coal mixes are used, which only produces coke having low mechanical strength. In the bulk operation in this process, the coal is packed by tamping into a coke charge mold, outside of the oven chamber. The tamping is done by means of free-falling tamping tools, and the coal is then fed into the oven chamber and coked in the usual manner.
The tamping tool rods, having friction linings attached thereto, are raised by eccentric cam discs which are firmly attached on counter-rotating cam shafts, which shafts are mounted alongside one another. The cams clamp the tamping tool rods by making contact with the rods, at a point on the cam circumference during each rotation. Because of the slippage associated with the rolling friction, between the lift cams and the tamping tool rod linings, these parts are subjected to a very high, and moreover, locally variable wear. An even and constant lifting stroke of the tamping tools is not assured any longer. After a longer period of use, such heavy wear may even result, that the individual tamping tools are not picked up and lifted anymore, by the associated lift cam pairs. The adjustment of the lift shafts for compensation of wear, or for that matter, the setting of the contact pressure between the tamping tool rods and lift cams is extremely expensive and time consuming.
Further, it is known to use eccentrically pivoted segmented discs, as so-called tamping tool locks, for clamping the raised tamping tool rods while the coal charge is charged into the oven chamber. These tamping locks are swivelable about horizontal axes. These tamping locks, by the action of their own weight and their eccentric support, clamp the tamping tool rods.
Another available proposal was to mount such tamping tool locks on a lifting arrangement, which then is moved up and down. The tamping tool locks clamp the tamping tool rods, when the lifting process is started, and lift the tamping tools. When in the uppermost position, the tamping tools are released by the action of a protrusion, firmly attached to the tamping lock rod, striking a fixed stop on the tamping device and thereby turning the tamping lock shafts.
The design of this lifting arrangement, as well as, the manner in which the tamping tool lock shafts are supported, are very complex. Furthermore, the extensive wear of the tamping tool rods and the tamping tool locks still persists. The tamping tool locks must rest against the stops until the corresponding tamping tool has fallen onto the coal, to be packed, so that, only then can the lifting gear be lowered. The lifting arrangement and the tamping tool rods are guided separately in the frame of the tamping device. This brings about the risk of jamming the tamping rods.
Because of slippage, the friction linings must be glued onto the tamping tool rods. Because of this, an expensive, heat resistant arrangement is required. Old friction linings must be ground off before new linings can be applied, requiring special suction devices and protective measures because of the high asbestos content of these linings.
The object, of this present invention, is to provide a device for the lifting of the tamping tools, as well as, a device for holding raised tamping tools in a tamping machine, which devices are especially simple in design, reliably minimizing slippage, and easily and inexpensively maintained. The lifting device should, especially, assure a constant tamping tool lifting stroke, during extended periods of operation.